Carbon black and process and apparatus for producing same



c; MATLQCK m PRODUCING SAME- CARBON BLACK AND PROCESS AND APPARATUS Filed. June 2', 1 921 ?atented Feb. &, i927.

d ed-r OEAWCE'Y l m F emm New roan, assrenon 'ro menace-mama li E3 aarfaa CARBON GQEPAEIY, E HOWE, ifiUImd h; COBWEAIIQN 0F DELAWAEE.

cannon areas has raocass'eun Application filed June 2,

The present invention relates to carbon black,.and.more particularly to an unproved carbon black product and to a process and a paratus for the roduction of carbon 5 b ack from hydrocar ons.' Carbon black has generally been produced heretofore for commercial purposes by the partial combustion of natural gas or hydrocarbons in such a manner as to obtain an im rfect admission and admixture of air with the hydrocarbons to the end that the 'complete and uniform combustion of the hydrocarbons should be avoidedand aportion of the hydrocarbons merely d1s'soc1ated l or partly oxidized to form carbon and other products. 'Through this artlal oxldatlon a small quantit of finely ivlded carbon was obtained in t e products of the decompos1- tion of partial combustion reaction. The suspended particles of carbon produced in this manner were thereupon separated from the gaseous products and collected either by introducing into or immediately abovethe flame a chill-plate or other device on which the carbon would adhere and form a deposit together with condensed or absorbed oils and tarsr When a'suflicientldeposit had acciimulated, the carbon was scraped from the plate together with iron scales .or rust and. the deposited oily or tarry products.

If a carbon free of an excess of oil or tarry products was desired, the deposited carbon was usually freed from the tar and oilby reheating the carbon after beingscraped 35 from the plate or reheating the plate before the removal of the carbon by passing the )late over succeeding flames. This reheat-- mg of the carbon in a mass tended however to produce in the resulting product dense, gray cokelike forms of carbon which impaired the quality ofthe carbon black. In some cases carbon black has been collected without the use of a chill plate, but in these casesalso the carbon has been contaminated with condensed or absorbed oily products.

The object of the present invention is to provide a carbon black substantially free of dense or cokelike forms of carbon and of oily or tarry substances.

Another object of the invention is to provide a process in which carbon of excellent quality may be efliciently and economically produced from hydrocarbons.

'A further object of the invention is to provide a process in which carbon may be mam-Us roa raonucmeeam.

. i 1am. Serial No. amass.

separated from gaseous products of cornbustion or dissociation of h drocarbons without contamination with oi y or tarry products present in the gases.

A still further object of the invention is to provide a process of producingcarbon black in which several grades or qualities of carbon black may be produced and other products may be recovered. v

A still further object of the invention is to provide an apparatus by which carbon may be produced from hydrocarbons and may be recovered in a substantially pure state and free .from oily substances and un desirable forms of carbon.

With these and other objects in view, the invention comprises the product, the process, and the apparatus described in the following specification and defined in the claims.

The various features of the invention are illustrated in the accompanying drawings in which: y i I Fig. 1, is a view partly in elevation and partly in vertical section of a preferred form of apparatus suitable for producing carbon black by the present invention.

Fig. 2 is a horizontal section of a carbon filtemn or separating means taken on line 2-2 0 Fig. 1, and

Fig. 3, is a sectional detail view of a portion of a filtering screen forming a part of a carbon separating element .of the apparatus illustrated in Figs. 1 and 2.

In the present invention the partial combustion or decomposition ofthe hydroca'rbons is accomplished in such a manner as to permit a control of the conditions governing the reaction, and the carbon thereby produced is separated from the gaseous or v'aporous products formed, in such a manner as to avoid its contamination with .oils or tars or other impurities present in the prodnets of the reaction. To this end the hydrocarbons are preferably burned in an enclosed chamber with a re lated amount of air, the quantity of-which 1s controlled in proportion to the hydrocarbons to obtain a desired par-,

vtial combustion or decomposition of the hydrocarbons and definite temperature and combustion conditions within the furnace. When the desired combustion or dissociation of the hydrocarbons has been obtained the products of the reaction are immediately removed from the furnace and the carbon is separated from the gaseous products in no which it is carried before sufiicient cooling of the gases or carbon has taken place to permit a substantial amount of oily or tarry products to condense or be absorbed in the separated carbon."

In separating the carbon from the gaseous reaction products the combustion gases are therefore passed directly from the furnace through a separatin screen which is protected from cooling or c illing action to prevent an excessive or uncontrolled coolin ofthe ases or carbon during the separating step.

he separated carbon is maintained at a temperature above the end point or condensing temperature of the tarry and oily vapors until it is removed from contact with the gaseous products of combustion. The gases passing through the filtering screen may carry with them a small amount of carbon which is too fine to be retained on the screen, or which from other causes may be .carried through the screens. The escaping gases also contain a considerable quantity of hydrocarbons, largely of the aromatic series, such for example as naphthaline, and of high boil ing points. To obtain these residual products the residual gases are therefore chilled or cooled to condense the oils and tars and are thereafter filtered to collect the carbon and tars as a secondary or by-product.

Referring more particularlyto the accom panying drawing, a regulated supply of gaseous hydrocarbons is supplied through a suply pipe 10 and a controlling valve 12 to hurners 14 positioned in the lower part of a furnace or combustion chamber 16. A regulated supply of air sufiicient to effect a partial combustion of the hydrocarbons is supplied to the furnace below the burners 14 through a supply pipe 19 and a control damper 18, to oxidize the hydrocarbons just sufficiently to obtain the desired temperature conditions and form a maximum of suspend cd carlgon of the desired quality. As the air pas cs upwardl into contact with the streams of hydrocar on gases from the burners 14, it is permitted to mix with the hydrocarbons and, upon the completion of the mixing, the gases are burned in the furnace at a short distance above theburners. A body or blanket 20 of hot or incandescent products of combustion is preferably maintained in the furnace extending upwardly from a short distance above the burners 14 and the completion of the mixing of the gases and air and partial combustion of the hydrocarbons takes place in this body or blanket of hot gases. By this manner of treatment the hydrocarbons are subjected in the body of gases to a substantially uniform temperature I throughout; out of contact with cold surfaces or cold gases. To avoid an uncontrolled local cooling of the gases immediately adjacent the walls of the furnace and consequent interference with the combustion and dissociation reactions, the furnace is preferably constructed of a suflicient thickness of fire brick or other material to reduce the transfer of heat throu hout to a minimum. As the gases reach t e upper part of the furnace the desired combustion or dissociation will have been completed, and the carbon is thereupon separated from the'gaseous products of reaction.

The separation of the carbon from the gases is accomplished without cooling either the carbon or the gases to a point at which oils or tars separate in substantial amounts. To this end the gases are withdrawn from the furnace through an outlet pipe 22 and enter a separating chamber 24 positioned adjacent to the upper part of the furnace. The gases are received in a lower compartment 26, formed in the chamber by a horizontal partition 28. From the compartment 26 the gases, together with the suspendedcarbon, pass upwardly through openings 30, Figs. 1 and 2, in the partition 28 and are received within tubular heat-resisting wire screens 32 of very fine mesh which are fastened at their lower ends to the edges of the openings 30 and are suspended at their upper ends in' an upper compartment 34 formed by the parti tion 28. The screens are suspended from the top' of the separator or screen chamber 24 by means of depending supports 36 to which caps 38, Fig. 3, forming the tops of the screens are attached. The gases are drawn into theinterior of, and through the meshes of, the'screens, which catch and retain the carbon articles.

The egree to which the gases may be permitted to cool is so controlled in relation to the furnace temperature that the temperature of the gases in the-chamber 24 andaccordingly of the separated carbon, do not a fall below approximately 900 degrees F; or below he and boiling point of the oily or tarry products in the gases at their respective pressures. As the separated carbon is surrounded by the gases passing through the screens it does not come into contact with the surfaces exposed to atmospheric cooling and therefore does not form an absorbent medium for oily vapors contained in the gases.

Should the gases be cooled by contact with the walls of the compartment 34 to an extent sufiicient to condense oily vapors, such cooling is prevented by insulating the walls of the chamber. v

From the separator chamber 34 the residual gases, together with any particles of carbon which may have passed through the screens, are withdrawn through a p1pe40 and cooled to obtain the residual vapors and carbon. For this. purpose the pipe 40 is provided with a suitable cooling means, such as the spray pipe 42, and with a thermometer 44 and the gases are cooled in the pipe v 40 by controlling the s iamdica ance w1 e in t e chamber 46. The bags yf' r m the-p pe 42 in accor tions of the thermometer'44, to obtain asufficiently -low temperature to condense the desiredaproducts and permit' them to be separat from the see by filters of canvas or other filtering abricwithout injuring the latter. 7 Thefigases from the pipe thereupon pass plates 58 and the gases are therefore cause to pass through the fabric of the bags and I the suspended condensed substances and 'carter similarly filter 24.

3 bon are filtered from the-gases. From the compartment 56the, gases are exhausted to the atmosphere through an exhaust pipe 60 by means of a fan 62. v

During'the filtration'of the carbon from the hot gases in the wire filter screen 24, a

deposit or 1a er of carbon is formed on the inner side'o the filtering tubes and gradually builds up to such an extent as to hmder or obstruct further passage of gases therethrou b. When this point is reached the flow 0%" the ases through the filter is interrupted and t e caflion deposit removed,

the gases being passed through another filarranged in parallel with the To this end dampers 64 and 66 are provided in the pipes 22 and 40 andare ordinaril held in horizontal, open, position during t e filtration operation by means of rcds 68, 70 and 72 connecting them to a'timmg device 74 which may be of any suitable type.

At regular periods of time, adjusted to the rate at which the carbon de os1t forms on the interior of the screens, t e dam ers 64 and 66 are closed by the timing mec an ism. 74 through the rods 72 and 68. At this time or immediately thereafter a damper 76,

the bottom of'the dani .which during the filtering operation closes.

communication between a chute 78, to which r 26 'conver s, is opened, to permit the disengaged cai' n to fall therethrough into a removingor conveying trough or pipe 80.

Simultaneously with or shortly after the closin of the dampers 64 and 66, the carbon deposit is swept from the inner surface of the screens by means of circular-brushes 82 or other removing means operated from the timing mechanism 74. .The brushes 82 have short bristles 84 extending outwardly into contact with the innerjsurface of the screens I 32 and upon being raised and lowered sweep the inner surface of the screens. The brushes are operated, and arenormally' supported w thin. theupper'; cap pprtion 358 I of the screens, ;.by means of supporting rods 66, Y

which extend upwardly within the supporting sleeves 36o't thecaps 38 through the t0% ]?f the filtering chamber 24.

e upper ends of the rods are suitabl supported by a supporting frame 88 whici may be weighted if necessary. by means of a weight 90 and ma be raised and-lowered bymeans of a cor 92 extending into the timing mechanism 74. T

'As-th frame 88 is lowered the brushes82 sweep over-the inner surfaceof the screens through the lower open ends of the screens onto sloping bottoms of the lower chamber 26 and fall through the chute 7 8 into the'conveyoryor removing tube 80. When substantially allof the carbon has been removed the. dampers 64 and 66 are opened, the dam er 76 is closed and thebrushes '84 are raise to theiruppermost position.

The brushes *82 may be formed of solid disks on plates perforated to permit carbon to fall through and prevent clogging of the upper partof the filtering tubes, or may be and remove the carbon wh'ich thereupon falls i in the form of an annular ring or wheel connected to the rod 86 b suitable spokes 87.

The screens 32 may e made of heat resist-- in or enduring wire or other materials capa le of resisting destruction or deterioration at temperatures somewhat above 800 degrees C. A large variety of metals -.is

available for forming these screens such as nichrome and some of the alloys of nickel or tungsten and other metals with steel. M oneP metal is however, preferred in 'general for the formation of these screens. Screens of fine mesh are required to filter the finely divided carbon produced in the process'. A- screen of about 300 mesh however, will ordinarily be sufliciently fine to collect a major portion of the carbon. The filtration of the carbon will be more complete and thorou h after a small deposit of carbon has forme which thereupon serves as a filter.

For this reason it is preferable to have the brushes 84 of such dimensions as to leave a flat thin deposit of carbon adhering to the inner surface of the screens. It is contemplated that other forms of filters and other separating apparatus may be employed butv filters of the general type described above are preferred since thegases cannot be subjected to anycooling action until after they have moved out of contact with the filtered carbon and the carbon .is completely surrounded by hot gases. v

The tem erature of the gases is cooled Sufliciently 1n the pipe 40 that they may be filtered through fa no and the filters 54 may therefore be made of any suitable filtration cloth. The carbon and other products may at intervals to throw the chains against the filters and to detach the deposit of carbon therefrom. For this purpose the blocks 58 are suspended from a frame Work 96, wh ch is supported from a rod 98, extending through the top of the filtering chamber 48 and may be given a slight rotary motion by -means of a crank 100 on the outside of the filterin chamber. The carbon detached from t e filters by the chains 94 drops through the openings 52 to the bottom of the chamber 46 which is sloped towards an exit chute 102. The chute 102 is normally closed by means of a damper 104 which is opened at intervals to permit filtered carbon and other substances to drop therethrough.

The carbon obtained through the hot filtration in the filtering chamber 24 is obtained substantially free from oily and tarry impurities, the oil and tar -contained, being normally below .15 to .20 of one per cent and is suitable for use in making rubber and for other uses in which a substantially oil free carbon is desired.

A high efliciency and economy is obtained in the operation of the process through an excellent control of the temperature and other conditions within the furnace I6.

' Only a very small art of the carbon produced passes throng the filters 24 and this.

carbon is moreover recovered in the filter 54 so that a very good recovery of the product is obtained.

A number of valuable by-products are obtained with the carbon collected on the filter 54, one of the principal constituents of these by-products being naphthalene. Q These products may be treated in any desired manner to separate the various constituents or may be carbonized to produce a denser. and

cheaper grade of carbonsuch as might'be used as a base for the production of absorbent or activated charcoal.

It is also contemplated that a number wire screens arranged in succession or in series may be used Where necessary and that other carbon separating apparatus may be employed in place otthe form of screen il- .lustrated above. T Having described the invention what is claimed as new is:

la- A process .of producing carbon black awh-ic h comprises partially oxidizing hydro- Lh bpns with a quantity of air suflicient to .only partially oxidize said hydrocarbons and separating the carbon, produced from the g-gaseous. products of combustion at a tem- -perature above 800 degrees 2.-A process of producing carbon black which comprises partially oxidizing h drocarbons with regulated quantities 0 air,

maintaining said gaseous roducts of combustion at a temperature a ove 800 degrees F., and filtering the carbon produced from said gaseous products of combustion at atemperature above 800 degrees F.

3. A process of producin .carbon black which comprises mixing hy rocarbons and air in definite controlled pro ortions insufiicient to completely burn sai hydrocarbons, igniting said mixture, maintaining the temperature of partial combustion above 800 degrees F., and filtering the carbon from the gaseous products of combustion while main-;

taining the temperature of said gases, and carbon above 800 degrees F.

4. A process of producing carbon black which comprises burning hydrocarbons and air in definite proportions in a combustion zone, withdrawing the roducts of combustion from said zone and filtering said products of combustion before permitting a substantial cooling of said products of combustion.

5. A process of producing carbon black which comprises forming carbon from hydrocarbons at high temperatures and separating the carbon. from the other products of said process at temperatures above 900 degrees F.

'6. An apparatus for producing carbon black which comprises a furnace having air andhydrocarbon supply means, said furnace being insulated to prevent a substantial loss of heat and a filtering means-adjac'ent the outlet;- of said furnace and adapted to separate carbon from gaseous products of combustion without tial cooling action.

7. An a paratus for producing carbon permitting a substanblack whic comprises. a furnace, burners in I said furnace, means for controllingthe supply of air to said furnace, means for control-. ling the supply of gases to said burners, means for removing the combustion products from said furnace and filtering means ar-' ranged to receive products of combustion directly from said furnace".

8. An apparatus -for producing carbon v black which comprises a combustion chamber, means for supplying combustibles and air in regulated proportions to said combustion chamber, said combustion chamber being substantially free of heat abstracting means for removing'the combustion pro note from said furnace-and a filter capable of enduring high temperatures arranged to re-' ceive gases directly from said combustion chamber. W

9. An apparatus for producing carbon black which comprises a combustion chamber, burners in the lower part of said, ohamber, means for supplying combustibles to said burners and 3.11 to said combustion p said combustion chamber.

- I gainer/1 bustion chamber'be' cessive abstraction 0 heat om said com.- bustion gases, and a filter. arranged to receive gases directly from the upper part of 10. An apparatus for producing carbon -black which comprises a combustion chamber, means for su plying regulated quantities of air and com ustibles to the lower part 'of said chamber, a filter arranged to receive gases from the upper part of said combustion chamber, said filter comprising a number of tubular wire screens of fine mesh and means for taking off carbon deposited on said screens while leaving a thin filtering deposit adjacent said screens.

11. An apparatus for producing carbonblack which comprises a combustion chamber, a metallic screen of fine mesh pos tioned to .receive gases from said furnace, 'means for cooling the exhaust gases from said filter and means for filtering" said cooled gases. I v

12. An apparatus for producing carbon black in combination with the furnace, anumber of filtering means connected to said furnace and to a carbon withdrawing means and means for closing said filter to said furnace and exit pipe and opening said filter to said carbon withdrawing-means.

13. An apparatus for separating carbon from hot gases which comprises a filtering chamber, a partition in said chamber, openings in said partition, cylindrical tubular filtering screens having open ends. fitted in said openings and supported above said partition, and brushes lightly j fitting the walls of said screens and. means for passing said brushes over said screens. v

14. An apparatus for separating carbon from hot gases which comprises a filtering chamber, a partition in said chamber, openings in said partition, cylindrical tubular filtering screens having open ends fitted in said openings and supported above sai partitions, and means for removing the last deposited portions of the carbon deposit on the surface of said screens while leaving the portion next the screen as a filtering layer.

15. In an apparatus for producing carbon black, the combination of a furnace havin an outlet; a heat resisting screen connecte ings and supported above said to said outlet arranged tog ifilter suspended carbon from the gasesfrom said furnace;

carbon deposited last', while leaving the underlying portions adjacent the screens as a filtering layer; 16. In an apparatus for producing carbon black, the combination of a furnace, screens arranged to receive gases from said furnace, means for closing communication'between screens and'said furnace, means for removing carbon from said screens and a common control means for said carbon removing means and said means for shutting com munication between said screen and said furnace. I

- 17; In an ap aratus for producing carbon black, the combination of a furnace, screens arranged to separate carbon particles from and. means for removing the portions ofv Y said gases, brushes arranged to sweep said openings in said -partition, and tubular screens of heat resistin wire having an open end mounted in sai openings.

19. -An apparatus for separating carbon from hot gases which com rises a filtering chamber, a artition insai chamber,-openings in sai partition, cylindrical tubular screens having open ends fitted in said openartitions, and brushes positioned within said tubular screens, the outer operative surfaces of said brushes terminating at a "point adjacent to but removed from the surface of the screens. 2 0. A process of producingcarbon black which comprises partially oxidizin hydrocarbons to produce finely divide carbon and separating said carbon from the gaseous products of combustion at a temperature above that at which a substantial amount of tars and oils may be separated with said carbon from said gaseous roducts of combustion, and continuously epositing a P01.

tion-only of said separated carbon.

In testimony whereof, I afix my signa .ture.

GHAUNOEY MATLOCK.

CERTIFICATE OF CORRECTION.

Patent No. 617,071. Granted February 8', 1927, to

QHAUNCEY MATLOCK.

It is hereby certified that error appears in the printed specification. of the above numbered patent requiring correction as follows: Page 3, line 92,. for the word "solid" read "molded"; page 4, line 120, claim 8, after the word "abstract-- in" insert the word "means"; and that the said Letters Patent should be read 3 with these corrections therein that the same may conform to the record of the I ease in the Patentflffi'ee.

Sign'ed'and-sesled this 17th day of May, A. ll). 1927.

. E. Moore, Seal. Acting Gommissioner of Patents. 

